test(fuzz): add deterministic compiler differential harness

[AetherAI3]

Summary

• add deterministic compiler/IR/runtime differential fuzz generation and archive campaigns
• cover the 53-entry catalog, receipt canonical/replay boundaries, and runtime risk gates without changing production code
• require unique valid bases, unique one-mutation invalid cases with exact diagnostics, and unique equivalence groups
• publish package 1.0.9; IR, receipt, Watchdog, and catalog versions remain unchanged

Evidence

• independent final code and release-envelope reviews GREEN
• focused adversarial: 649 passed
• full: 1005 passed, 2 skipped
• contribution checker: 53/53
• five-hashseed, two-ref, ten-worker archive stable with zero defects
• invalid 128/128 unique with exact class/location; equivalence 42/42 unique
• former receipt defect IDs absent
• exact wheel 1.0.9: 190 files, all 120 assets, catalog/receipt/risk audits clean
• four golden changes are identity.nanoVersion 1.0.8 to 1.0.9 only

No production compiler/runtime/receipt/risk/catalog changes, ambient nondeterminism, broker execution, or performance claim.